US8244789B1  Normalization of floating point operations in a programmable integrated circuit device  Google Patents
Normalization of floating point operations in a programmable integrated circuit device Download PDFInfo
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 US8244789B1 US8244789B1 US12/048,379 US4837908A US8244789B1 US 8244789 B1 US8244789 B1 US 8244789B1 US 4837908 A US4837908 A US 4837908A US 8244789 B1 US8244789 B1 US 8244789B1
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 G—PHYSICS
 G06—COMPUTING; CALCULATING; COUNTING
 G06F—ELECTRIC DIGITAL DATA PROCESSING
 G06F7/00—Methods or arrangements for processing data by operating upon the order or content of the data handled
 G06F7/38—Methods or arrangements for performing computations using exclusively denominational number representation, e.g. using binary, ternary, decimal representation
 G06F7/48—Methods or arrangements for performing computations using exclusively denominational number representation, e.g. using binary, ternary, decimal representation using noncontactmaking devices, e.g. tube, solid state device; using unspecified devices
 G06F7/499—Denomination or exception handling, e.g. rounding, overflow
 G06F7/49936—Normalisation mentioned as feature only

 G—PHYSICS
 G06—COMPUTING; CALCULATING; COUNTING
 G06F—ELECTRIC DIGITAL DATA PROCESSING
 G06F7/00—Methods or arrangements for processing data by operating upon the order or content of the data handled
 G06F7/38—Methods or arrangements for performing computations using exclusively denominational number representation, e.g. using binary, ternary, decimal representation
 G06F7/48—Methods or arrangements for performing computations using exclusively denominational number representation, e.g. using binary, ternary, decimal representation using noncontactmaking devices, e.g. tube, solid state device; using unspecified devices
 G06F7/483—Computations with numbers represented by a nonlinear combination of denominational numbers, e.g. rational numbers, logarithmic number system, floatingpoint numbers
 G06F7/487—Multiplying; Dividing
 G06F7/4876—Multiplying
Abstract
Description
This invention relates to performing floating point arithmetic operations in programmable integrated circuit devices such as, e.g., programmable logic devices (PLDs). More particularly, this invention relates to normalization techniques for floating point operations.
As applications for which PLDs are used increase in complexity, it has become more common to design PLDs to include specialized processing blocks in addition to blocks of generic programmable logic resources. Such specialized processing blocks may include a concentration of circuitry on a PLD that has been partly or fully hardwired to perform one or more specific tasks, such as a logical or a mathematical operation. A specialized processing block may also contain one or more specialized structures, such as an array of configurable memory elements. Examples of structures that are commonly implemented in such specialized processing blocks include: multipliers, arithmetic logic units (ALUs), barrelshifters, various memory elements (such as FIFO/LIFO/SIPO/RAM/ROM/CAM blocks and register files), AND/NAND/OR/NOR arrays, etc., or combinations thereof.
One particularly useful type of specialized processing block that has been provided on PLDs is a digital signal processing (DSP) block, which may be used to process, e.g., audio signals. Such blocks are frequently also referred to as multiplyaccumulate (“MAC”) blocks, because they include structures to perform multiplication operations, and sums and/or accumulations of multiplication operations.
For example, PLDs sold by Altera Corporation, of San Jose, Calif., as part of the STRATIX® family, include DSP blocks, each of which may include four 18by18 multipliers. Each of those DSP blocks also may include adders and registers, as well as programmable connectors (e.g., multiplexers) that allow the various components to be configured in different ways. In each such block, the multipliers can be configured not only as four individual 18by18 multipliers, but also as four smaller multipliers, or as one larger (36by36) multiplier. In addition, one 18by18 complex multiplication (which decomposes into two 18by18 multiplication operations for each of the real and imaginary parts) can be performed. In order to support four 18by18 multiplication operations, the block has 4×(18+18)=144 inputs. Similarly, the output of an 18by18 multiplication is 36 bits wide, so to support the output of four such multiplication operations, the block also has 36×4=144 outputs.
The arithmetic operations to be performed by a PLD frequently are floating point operations. However, to the extent that known PLDs, with or without DSP blocks or other specialized blocks or structures, including the aforementioned STRATIX® PLDs, can perform floating point operations at all, they operate in accordance with the IEEE7541985 standard, which requires that values be normalized at all times because the standard implies a leading “1”. However, normalization is expensive in terms of device area as well as operational latency.
The present invention relates to PLDs having improved floating point operation capabilities. In particular, the present invention carries out floating point operations with sufficient normalization to prevent overflow or underflow of the result. In some cases, that may mean that there is no normalization, which, as long as the result can be trusted—i.e., as long as it does not overflow or underflow or otherwise result in a loss of precision—is the most efficient mode of operation. In other cases, normalization to the full requirements of the IEEE7541985 standard may be performed because that is the only way to prevent overflow or underflow or other loss of precision. In intermediate cases, greater or lesser degrees of normalization may be carried out. In any case, the final result is typically normalized for IEEE7541985 compliance before it is output, because most external devices expect the result in that format.
Therefore, in accordance with the present invention, there is provided a method of configuring a programmable integrated circuit device to perform a floating point multiplication operation on multiplicand input values each formatted with a respective input mantissa/exponent pair, to provide an output value formatted with an output mantissa/exponent pair. The method includes configuring logic of the programmable integrated circuit device to examine the values to determine likelihood of overflow/underflow of the multiplication operation, and configuring logic of the programmable integrated circuit device to, based on that likelihood, adjust one of (a) at least one of the respective input mantissa and input exponent, and (b) the output mantissa and output exponent, to prevent overflow/underflow of the multiplication operation.
A programmable logic device so configured, and a machinereadable data storage medium encoded with software for performing the method, are also provided.
The above and other objects and advantages of the invention will be apparent upon consideration of the following detailed description, taken in conjunction with the accompanying drawings, in which like reference characters refer to like parts throughout, and in which:
Floating point numbers are commonplace for representing real numbers in scientific notation in computing systems. Examples of real numbers in scientific notation are:

 3.14159265_{10}×10° (π)
 2.718281828_{10}×10° (e)
 0.000000001_{10 }or 1.0_{10}×10^{−9 }(seconds in a nanosecond)
 3155760000_{10 }or 3.15576_{10}×10^{9 }(seconds in a century)
The first two examples are real numbers in the range of the lower integers, the third example represents a very small fraction, and the fourth example represents a very large integer. Floating point numbers in computing systems are designed to cover the large numeric range and diverse precision requirements shown in these examples. Fixed point number systems have a very limited window of representation which prevents them from representing very large or very small numbers simultaneously. The position of the notional binarypoint in fixed point numbers addresses this numeric range problem to a certain extent but does so at the expense of precision. With a floating point number the window of representation can move, which allows the appropriate amount of precision for the scale of the number.
Floating point representation is generally preferred over fixed point representation in computing systems because it permits an ideal balance of numeric range and precision. However, floating point representation requires more complex implementation compared to fixed point representation.
The IEEE7541985 standard is commonly used for floating point numbers. A floating point number includes three different parts: the sign of the number, its mantissa and its exponent. Each of these parts may be represented by a binary number and, in the IEEE7541985 format, have the following bit sizes:
Sign  Exponent  Bias  Mantissa  
Single  1 bit  8 bits  −127  23 bits 
Precision  [31]  [30 . . . 23]  [22 . . . 00]  
32Bit  
Double  1 bit  11 bits  −1023  52 bits 
Precision  [63]  [62 . . . 52]  [51 . . . 0]  
64Bit  
The exponent preferably is an unsigned binary number which, for the single precision format, ranges from 0 to 255. In order to represent a very small number, it is necessary to use negative exponents. To achieve this the exponent preferably has a negative bias associated with it. For singleprecision numbers, the bias preferably is −127. For example a value of 140 for the exponent actually represents (140−127)=13, and a value of 100 represents (100−127)=−27. For double precision numbers, the exponent bias preferably is −1023.
As discussed above, according to the standard, the mantissa is a normalized number—i.e., it has no leading zeroes and represents the precision component of a floating point number. Because the mantissa is stored in binary format, the leading bit can either be a 0 or a 1, but for a normalized number it will always be a 1. Therefore, in a system where numbers are always normalized, the leading bit need not be stored and can be implied, effectively giving the mantissa one extra bit of precision. Therefore, in single precision format, the mantissa typically includes 24 bits of precision.
However, the IEEE7541985 standard requires continuous normalization—i.e., normalization after every step of a multistep computation—to maintain the leading “1” to preserve accuracy. This is expensive in terms of PLD resources, as each normalization operation requires two steps—(1) finding the position of the “1”, and (2) shifting the fractional part to get a leading “1” (which is then eliminated, because it is implied).
Copending, commonlyassigned U.S. patent application Ser. No. 11/625,655, filed Jan. 22, 2007, the contents of which are hereby incorporated by reference herein in their entirety, discloses a method of performing floating point operations without an implied leading “1”, so that normalization is not required. The results are normalized only for output to outside devices that expect numbers according to the IEEE7541985 standard. However, as disclosed in the aforementioned application, normalization may be required at some intermediate steps to prevent loss of data. The present invention provides a way to perform that intermediate normalization without necessarily normalizing to the IEEE7541985 standard. Instead, only as much normalization as is required to prevent loss of data might be performed.
As mentioned above, normalization may not be required after every operation. For example, in an adder tree, the dynamic range of the mantissa can increase, but only by a maximum of one bit position per addition or subtraction operation. Therefore, the risk of overflow or underflow in addition or subtraction operations is small.
In multiplication, the effect of wordgrowth is much larger than in addition, as the wordgrowth is the sum of the wordgrowth of the inputs. For example, if the inputs to an operation are 8 and 8 (wordgrowth of 3 bits over the original 1.0), the maximum result of an addition is 16 (wordgrowth of 4 bits), while the maximum result for a multiplication is 64 (wordgrowth of 6 bits).
Nevertheless, even when two numbers are multiplied together, it may not be necessary that they be normalized. For example, the multiplier sizes natively supported by some PLDs (such as the 36by36 multipliers of the aforementioned STRATIX® family) are much larger than the mantissa sizes for single precision IEEE7541985 floating point operations, which are 24by24. Therefore, significant overflow and underflow space can be provided.
For example, for an IEEE7541985 input having 23 mantissa bits, four overflow bits and seven underflow bits can be provided in a 36bit representation, as follows: one sign bit, four overflow bits, one bit to make the implied leading “1” explicit, followed by 23 bits of the original mantissa data, leaving seven bits for underflow.
The result will be displaced from the original decimal place by the sum of the displacements of the inputs. For example, “001XX.XX . . . XX”×“001XX.XX . . . XX” will generate at least 1XXXX.XX, which is an overflow. This can happen very quickly. For a normalized number, the maximum value is 1.999 . . . 999_{10}. Adding two numbers together can generate a maximum of 3.999 . . . 9999_{10}. Multiplying two numbers that are the sum of two other numbers each can generate a maximum of 15.99999_{10}. If the total number of unnormalized inputs to a multiplier is less than six, then the maximum output of the multiplier is 31.99 . . . 99_{10}, which can be accommodated by the overflow bits. Of course, underflow can happen at the same rate, so it is possible that the precision of the number can decrease rapidly as well.
In a method according to the invention for configuring a programmable logic device to perform floating point operations, the programmable logic device may be configured to determine whether normalization is needed by examining whether overflow or underflow is possible in a datapath. One way of making such a determination is to examine the possible wordgrowth in the datapath assuming extremes of the possible inputs to the datapath. Another way of making such a determination is to examine the particular inputs to the datapath. Both techniques may be used in accordance with the invention.
In the discussion below of the latter technique, reference will be made to a “countleadingzeroes” (“CLZ”) circuit or function. This function is used to find the first significant digit. Although referred to as “count leading zeroes,” it may also count leading ones, such as in the case of signed numbers where the number is negative, in which case the first “0” is found. The number can then be normalized by left shifting it by the number of leading “zeros” (which may be ones or zeroes as just discussed)—i.e., by the index of the first significant bit. The result of normalizing based on the CLZ count may or may not be the same as IEEE7541985 normalization.
The examples that follow illustrate how normalization may be performed by a programmable integrated circuit device, such as a PLD, configured in accordance with embodiments of the invention.
In a first example, not shown in a drawing, the device is configured so that normalization is not performed on an input to a multiplier if the cluster feeding the multiplier cannot overflow the multiplier. For example, in the case of a numeric format as described above having four overflow bits, if the total number of sums in the two multiplier inputs is five or fewer, no normalization is required. It will be understood that if a different number of overflow bits is provided, the number of additions that allowed to be present in the input cluster before normalization is required should be adjusted accordingly.
In a second example, illustrated in
In a third example, illustrated in
In a fourth example, illustrated in
A fifth example (not illustrated) is a variant of the fourth example, except that instead of checking for underflow on a bitbybit basis, groups of a small number of bits (e.g., 46 bits), as programmed by the user, are checked (as, e.g., by ORing the bits in the group) until a group that contains nonzero bits is found. When a nonzero group is found, the number is normalized to a place in that group—e.g., to the center of the group. This will preserve the magnitude of the input to within at least a few places. In this case, full precision will probably be maintained in the final result in embodiments, such as the 36bit embodiment described above, in which the internal mantissa is much larger than the IEEE7541985 mantissa.
Devices configured according to the remaining examples normalize the output, rather than the inputs. This may cut the required normalization circuitry or logic approximately in half. Thus, in these examples, shown in
In the example shown in
In the example shown in
Thus, the method of the invention configures a programmable integrated circuit device, such as a PLD, to examine the values (either input values or output values) associated with a multiplication operation in a programmable integrated circuit device and to adjust either the input or output values accordingly to prevent overflow. A device configured in accordance with the method can examine and adjust the input values, examine and adjust the output value, or examine the input values and adjust the output value.
The adjustment may be the same as normalizing to a standard such as the IEEE7541985 standard, but need not be, and will depend on the CLZ count when the values are examined. It will be apparent that the adjustment is least likely to be same as normalization when the examination and/or adjustment of the values is carried out on a groupsofbits basis rather than a bitbybit basis.
Instructions for carrying out the method according to this invention may be encoded on a machinereadable medium, to be executed by a suitable computer or similar device to implement the method of the invention for programming or configuring programmable integrated circuit devices to perform operations as described above. For example, a personal computer may be equipped with an interface to which a programmable integrated circuit device can be connected, and the personal computer can be used by a user to program the programmable integrated circuit device using a suitable software tool, such as the QUARTUS® II software available from Altera Corporation, of San Jose, Calif.
The magnetic domains of coating 602 of medium 600 are polarized or oriented so as to encode, in manner which may be conventional, a machineexecutable program, for execution by a programming system such as a personal computer or other computer or similar system, having a socket or peripheral attachment into which the PLD to be programmed may be inserted, to configure appropriate portions of the PLD, including its specialized processing blocks, if any, in accordance with the invention.
In the case of a CDbased or DVDbased medium, as is well known, coating 702 is reflective and is impressed with a plurality of pits 703, arranged on one or more layers, to encode the machineexecutable program. The arrangement of pits is read by reflecting laser light off the surface of coating 702. A protective coating 704, which preferably is substantially transparent, is provided on top of coating 702.
In the case of magnetooptical disk, as is well known, coating 702 has no pits 703, but has a plurality of magnetic domains whose polarity or orientation can be changed magnetically when heated above a certain temperature, as by a laser (not shown). The orientation of the domains can be read by measuring the polarization of laser light reflected from coating 702. The arrangement of the domains encodes the program as described above.
Thus it is seen that a method for normalizing floating point operations, a programmable integrated circuit device programmed to perform the method, and software for carrying out the programming, have been provided.
A PLD 90 programmed according to the present invention may be used in many kinds of electronic devices. One possible use is in a data processing system 900 shown in
System 900 can be used in a wide variety of applications, such as computer networking, data networking, instrumentation, video processing, digital signal processing, or any other application where the advantage of using programmable or reprogrammable logic is desirable. PLD 90 can be used to perform a variety of different logic functions. For example, PLD 90 can be configured as a processor or controller that works in cooperation with processor 901. PLD 90 may also be used as an arbiter for arbitrating access to a shared resources in system 900. In yet another example, PLD 90 can be configured as an interface between processor 901 and one of the other components in system 900. It should be noted that system 900 is only exemplary, and that the true scope and spirit of the invention should be indicated by the following claims.
Various technologies can be used to implement PLDs 90 as described above and incorporating this invention.
It will be understood that the foregoing is only illustrative of the principles of the invention, and that various modifications can be made by those skilled in the art without departing from the scope and spirit of the invention. For example, the various elements of this invention can be provided on a programmable integrated circuit device in any desired number and/or arrangement. One skilled in the art will appreciate that the present invention can be practiced by other than the described embodiments, which are presented for purposes of illustration and not of limitation, and the present invention is limited only by the claims that follow.
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US20130113543A1 (en) *  20111109  20130509  Leonid Dubrovin  Multiplication dynamic range increase by on the fly data scaling 
CN104778028A (en) *  20140115  20150715  Arm 有限公司  Multiply adder 
CN104778028B (en) *  20140115  20190607  Arm 有限公司  Adder and multiplier 
Citations (232)
Publication number  Priority date  Publication date  Assignee  Title 

US3473160A (en)  19661010  19691014  Stanford Research Inst  Electronically controlled microelectronic cellular logic array 
US4156927A (en)  19760811  19790529  Texas Instruments Incorporated  Digital processor system with direct access memory 
US4179746A (en)  19760719  19791218  Texas Instruments Incorporated  Digital processor system with conditional carry and status function in arithmetic unit 
US4212076A (en)  19760924  19800708  Giddings & Lewis, Inc.  Digital computer structure providing arithmetic and boolean logic operations, the latter controlling the former 
US4215406A (en)  19720822  19800729  Westinghouse Electric Corp.  Digital computer monitored and/or operated system or process which is structured for operation with an improved automatic programming process and system 
US4215407A (en)  19720822  19800729  Westinghouse Electric Corp.  Combined file and directory system for a process control digital computer system 
US4422155A (en)  19810401  19831220  American Microsystems, Inc.  Multiplier/adder circuit 
US4484259A (en)  19800213  19841120  Intel Corporation  Fraction bus for use in a numeric data processor 
US4521907A (en)  19820525  19850604  American Microsystems, Incorporated  Multiplier/adder circuit 
US4597053A (en)  19830701  19860624  Codex Corporation  Twopass multiplier/accumulator circuit 
US4623961A (en)  19840307  19861118  Westinghouse Electric Corp.  Programmable controller having automatic contact line solving 
US4682302A (en)  19841214  19870721  Motorola, Inc.  Logarithmic arithmetic logic unit 
US4718057A (en)  19850830  19880105  Advanced Micro Devices, Inc.  Streamlined digital signal processor 
US4727508A (en)  19841214  19880223  Motorola, Inc.  Circuit for adding and/or subtracting numbers in logarithmic representation 
US4791590A (en)  19851119  19881213  Cornell Research Foundation, Inc.  High performance signal processor 
US4799004A (en)  19870126  19890117  Kabushiki Kaisha Toshiba  Transfer circuit for operation test of LSI systems 
US4823295A (en)  19861110  19890418  Harris Corp.  High speed signal processor 
US4839847A (en)  19870414  19890613  Harris Corp.  Nclock, nbitserial multiplier 
US4871930A (en)  19880505  19891003  Altera Corporation  Programmable logic device with array blocks connected via programmable interconnect 
US4912345A (en)  19881229  19900327  SgsThomson Microelectronics, Inc.  Programmable summing functions for programmable logic devices 
US4967160A (en)  19880624  19901030  ThomsonCsf  Frequency multiplier with programmable order of multiplication 
US4982354A (en)  19870528  19910101  Mitsubishi Denki Kabushiki Kaisha  Digital finite impulse response filter and method 
US4994997A (en)  19870925  19910219  U.S. Philips Corporation  Pipelinetype serial multiplier circuit 
US5122685A (en)  19910306  19920616  Quicklogic Corporation  Programmable application specific integrated circuit and logic cell therefor 
US5128559A (en)  19890929  19920707  SgsThomson Microelectronics, Inc.  Logic block for programmable logic devices 
EP0498066A2 (en)  19910208  19920812  Hitachi, Ltd.  Programmable logic controller 
US5175702A (en)  19900718  19921229  International Business Machines Corporation  Digital signal processor architecture with plural multiply/accumulate devices 
US5208491A (en)  19920107  19930504  Washington Research Foundation  Field programmable gate array 
USRE34363E (en)  19840312  19930831  Xilinx, Inc.  Configurable electrical circuit having configurable logic elements and configurable interconnects 
US5267187A (en)  19900510  19931130  Xilinx Inc  Logic structure and circuit for fast carry 
US5296759A (en)  19910829  19940322  National Semiconductor Corporation  Diagonal wiring between abutting logic cells in a configurable logic array 
EP0606653A1 (en)  19930104  19940720  Texas Instruments Incorporated  Field programmable distributed processing memory 
US5338983A (en)  19911028  19940816  Texas Instruments Incorporated  Application specific exclusive of based logic module architecture for FPGAs 
US5349250A (en)  19930902  19940920  Xilinx, Inc.  Logic structure and circuit for fast carry 
US5357152A (en)  19921110  19941018  Infinite Technology Corporation  Logic system of logic networks with programmable selected functions and programmable operational controls 
US5371422A (en)  19910903  19941206  Altera Corporation  Programmable logic device having multiplexers and demultiplexers randomly connected to global conductors for interconnections between logic elements 
US5381357A (en)  19930528  19950110  Grumman Corporation  Complex adaptive fir filter 
US5404324A (en)  19931101  19950404  HewlettPackard Company  Methods and apparatus for performing division and square root computations in a computer 
US5424589A (en)  19930212  19950613  The Board Of Trustees Of The Leland Stanford Junior University  Electrically programmable interchip interconnect architecture 
GB2286737A (en)  19940217  19950823  Pilkington Germany No 2 Ltd  ASIC with multiple internal reconfiguration stores 
US5446651A (en)  19931130  19950829  Texas Instruments Incorporated  Split multiply operation 
US5451948A (en)  19940228  19950919  Cubic Communications, Inc.  Apparatus and method for combining analog and digital automatic gain control in receivers with digital signal processing 
US5452231A (en)  19881005  19950919  Quickturn Design Systems, Inc.  Hierarchically connected reconfigurable logic assembly 
US5452375A (en)  19930524  19950919  Sagem S.A.  Digital image processing circuitry 
US5457644A (en)  19930820  19951010  Actel Corporation  Field programmable digital signal processing array integrated circuit 
US5465375A (en)  19920114  19951107  France Telecom  Multiprocessor system with cascaded modules combining processors through a programmable logic cell array 
US5465226A (en)  19900320  19951107  Fujitsu Limited  High speed digital parallel multiplier 
US5483178A (en)  19930329  19960109  Altera Corporation  Programmable logic device with logic block outputs coupled to adjacent logic block output multiplexers 
US5497498A (en)  19921105  19960305  Giga Operations Corporation  Video processing module using a second programmable logic device which reconfigures a first programmable logic device for data transformation 
US5500828A (en)  19930528  19960319  Texas Instruments Incorporated  Apparatus, system and methods for distributed signal processing 
EP0380456B1 (en)  19890125  19960605  SGSTHOMSON MICROELECTRONICS S.r.l.  Field programmable logic and analogic integrated circuit 
US5528550A (en)  19930528  19960618  Texas Instruments Incorporated  Apparatus, systems and methods for implementing memory embedded search arithmetic logic unit 
US5537601A (en)  19930721  19960716  Hitachi, Ltd.  Programmable digital signal processor for performing a plurality of signal processings 
US5546018A (en)  19930902  19960813  Xilinx, Inc.  Fast carry structure with synchronous input 
US5550993A (en)  19890504  19960827  Texas Instruments Incorporated  Data processor with sets of two registers where both registers receive identical information and when context changes in one register the other register remains unchanged 
US5559450A (en)  19950727  19960924  Lucent Technologies Inc.  Field programmable gate array with multiport RAM 
US5563819A (en)  19940331  19961008  Cirrus Logic, Inc.  Fast high precision discretetime analog finite impulse response filter 
US5563526A (en)  19940103  19961008  Texas Instruments Incorporated  Programmable mixedmode integrated circuit architecture 
US5570040A (en)  19950322  19961029  Altera Corporation  Programmable logic array integrated circuit incorporating a firstin firstout memory 
US5570039A (en)  19950727  19961029  Lucent Technologies Inc.  Programmable function unit as parallel multiplier cell 
US5572148A (en)  19950322  19961105  Altera Corporation  Programmable logic array integrated circuit with generalpurpose memory configurable as a random access or FIFO memory 
US5581501A (en)  19950817  19961203  Altera Corporation  Nonvolatile SRAM cells and cell arrays 
US5590350A (en)  19931130  19961231  Texas Instruments Incorporated  Three input arithmetic logic unit with mask generator 
US5594366A (en)  19940504  19970114  Atmel Corporation  Programmable logic device with regional and universal signal routing 
US5594912A (en)  19930809  19970114  Siemens Aktiengesellschaft  Digital signal processing device with optimized ALU circuit and logic block for controlling one of two registers based on the contents of the multiplication register 
US5596763A (en)  19931130  19970121  Texas Instruments Incorporated  Three input arithmetic logic unit forming mixed arithmetic and boolean combinations 
US5606266A (en)  19941104  19970225  Altera Corporation  Programmable logic array integrated circuits with enhanced output routing 
US5617058A (en)  19951113  19970401  Apogee Technology, Inc.  Digital signal processing for linearization of small input signals to a tristate power switch 
EP0555092B1 (en)  19920207  19970514  Questech Limited  Improvements in and relating to digital filters 
US5633601A (en)  19950310  19970527  Texas Instruments Incorporated  Field programmable gate array logic module configurable as combinational or sequential circuits 
US5636368A (en)  19941223  19970603  Xilinx, Inc.  Method for programming complex PLD having more than one function block type 
US5636150A (en)  19920806  19970603  Sharp Kabushiki Kaisha  Data driven type digital filter unit and data driven type information processor including the same 
US5640578A (en)  19931130  19970617  Texas Instruments Incorporated  Arithmetic logic unit having plural independent sections and register storing resultant indicator bit from every section 
US5644522A (en)  19931130  19970701  Texas Instruments Incorporated  Method, apparatus and system for multiply rounding using redundant coded multiply result 
US5646545A (en)  19950818  19970708  Xilinx, Inc.  Time multiplexed programmable logic device 
US5648732A (en)  19951004  19970715  Xilinx, Inc.  Field programmable pipeline array 
US5652903A (en)  19941101  19970729  Motorola, Inc.  DSP coprocessor for use on an integrated circuit that performs multiple communication tasks 
US5655069A (en)  19940729  19970805  Fujitsu Limited  Apparatus having a plurality of programmable logic processing units for selfrepair 
EP0461798B1 (en)  19900614  19970813  Advanced Micro Devices, Inc.  Configurable interconnect structure 
US5664192A (en)  19941214  19970902  Motorola, Inc.  Method and system for accumulating values in a computing device 
US5689195A (en)  19950517  19971118  Altera Corporation  Programmable logic array integrated circuit devices 
US5696708A (en)  19950330  19971209  Crystal Semiconductor  Digital filter with decimated frequency response 
GB2283602B (en)  19931104  19980304  Altera Corp  Implementation of redundancy on a programmable logic device 
US5729495A (en)  19950929  19980317  Altera Corporation  Dynamic nonvolatile memory cell 
US5740404A (en)  19930927  19980414  Hitachi America Limited  Digital signal processor with onchip select decoder and wait state generator 
US5744980A (en)  19960216  19980428  Actel Corporation  Flexible, highperformance static RAM architecture for fieldprogrammable gate arrays 
US5744991A (en)  19951016  19980428  Altera Corporation  System for distributing clocks using a delay lock loop in a programmable logic circuit 
US5754459A (en)  19960208  19980519  Xilinx, Inc.  Multiplier circuit design for a programmable logic device 
US5761483A (en)  19950818  19980602  Xilinx, Inc.  Optimizing and operating a time multiplexed programmable logic device 
US5764555A (en)  19960313  19980609  International Business Machines Corporation  Method and system of rounding for division or square root: eliminating remainder calculation 
US5768613A (en)  19900706  19980616  Advanced Micro Devices, Inc.  Computing apparatus configured for partitioned processing 
US5777912A (en)  19960328  19980707  Crystal Semiconductor Corporation  Linear phase finite impulse response filter with preaddition 
US5784636A (en)  19960528  19980721  National Semiconductor Corporation  Reconfigurable computer architecture for use in signal processing applications 
US5790446A (en)  19950705  19980804  Sun Microsystems, Inc.  Floating point multiplier with reduced critical paths using delay matching techniques 
US5794067A (en)  19941003  19980811  Ricoh Company, Ltd.  Digital signal processing device 
US5801546A (en)  19950104  19980901  Xilinx, Inc.  Interconnect architecture for field programmable gate array using variable length conductors 
US5805913A (en)  19931130  19980908  Texas Instruments Incorporated  Arithmetic logic unit with conditional register source selection 
US5805477A (en)  19960926  19980908  HewlettPackard Company  Arithmetic cell for field programmable devices 
US5812562A (en)  19961115  19980922  Samsung Electronics Company, Ltd.  Low cost emulation scheme implemented via clock control using JTAG controller in a scan environment 
US5812479A (en)  19910903  19980922  Altera Corporation  Programmable logic array integrated circuits 
US5815422A (en)  19970124  19980929  Vlsi Technology, Inc.  Computerimplemented multiplication with shifting of patternproduct partials 
US5821776A (en)  19970131  19981013  Actel Corporation  Field programmable gate array with mask programmed analog function circuits 
US5825202A (en)  19960926  19981020  Xilinx, Inc.  Integrated circuit with field programmable and application specific logic areas 
US5838165A (en)  19960821  19981117  Chatter; Mukesh  High performance self modifying onthefly alterable logic FPGA, architecture and method 
US5841684A (en)  19970124  19981124  Vlsi Technology, Inc.  Method and apparatus for computer implemented constant multiplication with multipliers having repeated patterns including shifting of replicas and patterns having at least two digit positions with nonzero values 
US5847579A (en)  19970320  19981208  Xilinx, Inc.  Programmable logic array with improved interconnect structure 
US5859878A (en)  19950831  19990112  Northrop Grumman Corporation  Common receive module for a programmable digital radio 
US5869979A (en)  19960405  19990209  Altera Corporation  Technique for preconditioning I/Os during reconfiguration 
US5872380A (en)  19941102  19990216  Lsi Logic Corporation  Hexagonal sense cell architecture 
US5874834A (en)  19970304  19990223  Xilinx, Inc.  Field programmable gate array with distributed gatearray functionality 
US5878250A (en)  19970407  19990302  Altera Corporation  Circuitry for emulating asynchronous register loading functions 
EP0411491B1 (en)  19890802  19990303  Cyrix Corporation  Method and apparatus for performing division using a rectangular aspect ratio multiplier 
US5880981A (en)  19960812  19990309  Hitachi America, Ltd.  Method and apparatus for reducing the power consumption in a programmable digital signal processor 
EP0905906A2 (en)  19970926  19990331  Lucent Technologies Inc.  Hybrid programmable gate arrays 
US5892962A (en)  19961112  19990406  Lucent Technologies Inc.  FPGAbased processor 
US5894228A (en)  19960110  19990413  Altera Corporation  Tristate structures for programmable logic devices 
US5898602A (en)  19960125  19990427  Xilinx, Inc.  Carry chain circuit with flexible carry function for implementing arithmetic and logical functions 
US5931898A (en)  19970225  19990803  Lucent Technologies Inc  Finite impulse response filter 
US5942914A (en)  19961025  19990824  Altera Corporation  PLD with split multiplexed inputs from global conductors 
US5944774A (en)  19970926  19990831  Ericsson Inc.  Methods apparatus and computer program products for accumulating logarithmic values 
US5949710A (en)  19960410  19990907  Altera Corporation  Programmable interconnect junction 
US5951673A (en)  19940125  19990914  Yamaha Corporation  Digital signal processing device capable of selectively imparting effects to input data 
US5956265A (en)  19960607  19990921  Lewis; James M.  Boolean digital multiplier 
US5960193A (en)  19931130  19990928  Texas Instruments Incorporated  Apparatus and system for sum of plural absolute differences 
US5959871A (en)  19931223  19990928  Analogix/Portland State University  Programmable analog array circuit 
US5961635A (en)  19931130  19991005  Texas Instruments Incorporated  Three input arithmetic logic unit with barrel rotator and mask generator 
US5963050A (en)  19970226  19991005  Xilinx, Inc.  Configurable logic element with fast feedback paths 
US5968196A (en)  19980421  19991019  Atmel Corporation  Configuration control in a programmable logic device using nonvolatile elements 
US5970254A (en)  19970627  19991019  Cooke; Laurence H.  Integrated processor and programmable data path chip for reconfigurable computing 
US5978260A (en)  19950818  19991102  Xilinx, Inc.  Method of time multiplexing a programmable logic device 
US5982195A (en)  19970220  19991109  Altera Corporation  Programmable logic device architectures 
US5986465A (en)  19960409  19991116  Altera Corporation  Programmable logic integrated circuit architecture incorporating a global shareable expander 
US5991898A (en)  19970310  19991123  Mentor Graphics Corporation  Arithmetic builtin self test of multiple scanbased integrated circuits 
US5991788A (en)  19970314  19991123  Xilinx, Inc.  Method for configuring an FPGA for large FFTs and other vector rotation computations 
US5995748A (en)  19931130  19991130  Texas Instruments Incorporated  Three input arithmetic logic unit with shifter and/or mask generator 
US5999015A (en)  19970220  19991207  Altera Corporation  Logic region resources for programmable logic devices 
US5999990A (en)  19980518  19991207  Motorola, Inc.  Communicator having reconfigurable resources 
US6006321A (en)  19970613  19991221  Malleable Technologies, Inc.  Programmable logic datapath that may be used in a field programmable device 
US6005806A (en)  19960314  19991221  Altera Corporation  Nonvolatile configuration cells and cell arrays 
US6009451A (en)  19961122  19991228  Lucent Technologies Inc.  Method for generating barrel shifter result flags directly from input data 
US6020759A (en)  19970321  20000201  Altera Corporation  Programmable logic array device with random access memory configurable as product terms 
US6021423A (en)  19970926  20000201  Xilinx, Inc.  Method for parallelefficient configuring an FPGA for large FFTS and other vector rotation computations 
US6029187A (en)  19971028  20000222  Atmel Corporation  Fast regular multiplier architecture 
US6031763A (en)  19960816  20000229  Altera Corporation  Evaluation of memory cell characteristics 
US6052755A (en)  19940328  20000418  Altera Corporation  Programming circuits and techniques for programmable logic 
US6052327A (en)  19971014  20000418  Altera Corporation  Dualport programmable logic device variable depth and width memory array 
US6065131A (en)  19971126  20000516  International Business Machines Corporation  Multispeed DSP kernel and clock mechanism 
US6066960A (en)  19980521  20000523  Altera Corporation  Programmable logic device having combinational logic at inputs to logic elements within logic array blocks 
US6069487A (en)  19971014  20000530  Altera Corporation  Programmable logic device circuitry for improving multiplier speed and/or efficiency 
US6073154A (en)  19980626  20000606  Xilinx, Inc.  Computing multidimensional DFTs in FPGA 
US6072994A (en)  19950831  20000606  Northrop Grumman Corporation  Digitally programmable multifunction radio system architecture 
US6075381A (en)  19980121  20000613  Micron Electronics, Inc.  Programmable logic block in an integrated circuit 
US6084429A (en)  19980424  20000704  Xilinx, Inc.  PLD having a window pane architecture with segmented and staggered interconnect wiring between logic block arrays 
US6085317A (en)  19970815  20000704  Altera Corporation  Reconfigurable computer architecture using programmable logic devices 
US6091765A (en)  19971103  20000718  Harris Corporation  Reconfigurable radio system architecture 
US6091261A (en)  19981112  20000718  Sun Microsystems, Inc.  Apparatus and method for programmable delays using a boundaryscan chain 
US6094726A (en)  19980205  20000725  George S. Sheng  Digital signal processor using a reconfigurable array of macrocells 
US6098163A (en)  19931130  20000801  Texas Instruments Incorporated  Three input arithmetic logic unit with shifter 
US6097988A (en)  19980210  20000801  Advanced Micro Devices, Inc.  Logic system and method employing multiple configurable logic blocks and capable of implementing a state machine using a minimum amount of configurable logic 
US6107824A (en)  19971016  20000822  Altera Corporation  Circuitry and methods for internal interconnection of programmable logic devices 
US6107821A (en)  19990208  20000822  Xilinx, Inc.  Onchip logic analysis and method for using the same 
US6107820A (en)  19970523  20000822  Altera Corporation  Redundancy circuitry for programmable logic devices with interleaved input circuits 
US6130554A (en)  19960621  20001010  Quicklogic Corporation  Programmable integrated circuit having a test circuit for testing the integrity of routing resource structures 
GB2318198B (en)  19961010  20001025  Altera Corp  Architectures for programmable logic devices 
US6140839A (en)  19980513  20001031  Kaviani; Alireza S.  Computational field programmable architecture 
US6154049A (en)  19980327  20001128  Xilinx, Inc.  Multiplier fabric for use in field programmable gate arrays 
US6157210A (en)  19971016  20001205  Altera Corporation  Programmable logic device with circuitry for observing programmable logic circuit signals and for preloading programmable logic circuits 
EP1058185A1 (en)  19990531  20001206  Motorola, Inc.  A multiply and accumulate apparatus and a method thereof 
US6163788A (en)  19980625  20001219  Industrial Technology Research Institute  Programmable finite impulse response processor with scalable dynamic data range 
US6167415A (en)  19980210  20001226  Lucent Technologies, Inc.  Recursive digital filter with reset 
US6175849B1 (en)  19980210  20010116  Lucent Technologies, Inc.  System for digital filtering in a fixed number of clock cycles 
US6215326B1 (en)  19981118  20010410  Altera Corporation  Programmable logic device architecture with superregions having logic regions and a memory region 
US6226735B1 (en)  19980508  20010501  Broadcom  Method and apparatus for configuring arbitrary sized data paths comprising multiple context processing elements 
US6243729B1 (en)  19981231  20010605  Texas Instruments Incorporated  Digital finiteimpulseresponse (FIR) filter with a modified architecture based on high order RadixN numbering 
US6246258B1 (en)  19990621  20010612  Xilinx, Inc.  Realizing analogtodigital converter on a digital programmable integrated circuit 
US6279021B1 (en)  19980130  20010821  Sanyo Electric Co. Ltd.  Digital filters 
US6286024B1 (en)  19970918  20010904  Kabushiki Kaisha Toshiba  Highefficiency multiplier and multiplying method 
EP0927393B1 (en)  19960923  20011017  ARM Limited  Digital signal processing integrated circuit architecture 
US6314551B1 (en)  19980622  20011106  Morgan Stanley & Co. Incorporated  System processing unit extended with programmable logic for plurality of functions 
US6314442B1 (en)  19980619  20011106  Mitsubishi Denki Kabushiki Kaisha  Floatingpoint arithmetic unit which specifies a least significant bit to be incremented 
US6321246B1 (en)  19980916  20011120  Cirrus Logic, Inc.  Linear phase FIR sinc filter with multiplexing 
US6323680B1 (en)  19990304  20011127  Altera Corporation  Programmable logic device configured to accommodate multiplication 
US6359468B1 (en)  19990304  20020319  Altera Corporation  Programmable logic device with carry lookahead 
US6362650B1 (en)  20000518  20020326  Xilinx, Inc.  Method and apparatus for incorporating a multiplier into an FPGA 
US6367003B1 (en)  19980304  20020402  Micron Technology, Inc.  Digital signal processor having enhanced utilization of multiply accumulate (MAC) stage and method 
US6366944B1 (en)  19990115  20020402  Razak Hossain  Method and apparatus for performing signed/unsigned multiplication 
EP0657803B1 (en)  19931130  20020502  Texas Instruments Incorporated  Three input arithmetic logic unit 
EP0660227B1 (en)  19931130  20020502  Texas Instruments Incorporated  Three input arithmetic logic unit forming the sum of a first and a second boolean combination of the inputs 
US6407694B1 (en)  20000614  20020618  Raytheon Company  General purpose filter 
US6407576B1 (en)  19990304  20020618  Altera Corporation  Interconnection and input/output resources for programmable logic integrated circuit devices 
US20020089348A1 (en)  20001002  20020711  Martin Langhammer  Programmable logic integrated circuit devices including dedicated processor components 
EP0868659B1 (en)  19951218  20020807  Abb Ab  Torque transducer 
US6438570B1 (en)  19990721  20020820  Xilinx, Inc.  FPGA implemented bitserial multiplier and infinite impulse response 
US6453382B1 (en)  19981105  20020917  Altera Corporation  Content addressable memory encoded outputs 
US6467017B1 (en)  19980623  20021015  Altera Corporation  Programmable logic device having embedded dualport random access memory configurable as singleport memory 
US6480980B2 (en)  19990310  20021112  Nec Electronics, Inc.  Combinational test pattern generation method and apparatus 
US6483343B1 (en)  20001229  20021119  Quicklogic Corporation  Configurable computational unit embedded in a programmable device 
US6538470B1 (en)  20000918  20030325  Altera Corporation  Devices and methods with programmable logic and digital signal processing regions 
US6542000B1 (en)  19990730  20030401  Iowa State University Research Foundation, Inc.  Nonvolatile programmable logic devices 
US6557092B1 (en)  19990329  20030429  Greg S. Callen  Programmable ALU 
US6556044B2 (en)  20010918  20030429  Altera Corporation  Programmable logic device including multipliers and configurations thereof to reduce resource utilization 
US20030088757A1 (en)  20010502  20030508  Joshua Lindner  Efficient high performance data operation element for use in a reconfigurable logic environment 
US6571268B1 (en)  19981006  20030527  Texas Instruments Incorporated  Multiplier accumulator circuits 
US6574762B1 (en)  20000331  20030603  Lsi Logic Corporation  Use of a scan chain for configuration of BIST unit operation 
EP0909028B1 (en)  19970916  20030702  Tektronix, Inc.  Fir filter for programmable decimation 
US6591283B1 (en)  19981224  20030708  Stmicroelectronics N.V.  Efficient interpolator for high speed timing recovery 
US6600788B1 (en)  19990910  20030729  Xilinx, Inc.  Narrowband filter including sigmadelta modulator implemented in a programmable logic device 
US6628140B2 (en)  20000918  20030930  Altera Corporation  Programmable logic devices with functionspecific blocks 
US6700581B2 (en)  20020301  20040302  3D Labs Inc., Ltd.  Incircuit test using scan chains 
US20040064770A1 (en)  20020930  20040401  Xin Weizhuang (Wayne)  Programmable state machine of an integrated circuit 
US6725441B1 (en)  20000322  20040420  Xilinx, Inc.  Method and apparatus for defining and modifying connections between logic cores implemented on programmable logic devices 
US20040083412A1 (en)  20021025  20040429  International Business Machines Corporation  Testing logic and embedded memory in parallel 
US6731133B1 (en)  20000902  20040504  Actel Corporation  Routing structures for a tileable fieldprogrammable gate array architecture 
US6745254B2 (en)  19990330  20040601  Siemens Energy & Automation, Inc.  Programmable logic controller method, system and apparatus 
US6774669B1 (en)  20021230  20040810  Actel Corporation  Field programmable gate array freeway architecture 
US6781408B1 (en)  20020424  20040824  Altera Corporation  Programmable logic device with routing channels 
US6788104B2 (en)  20010629  20040907  Stmicroelectronics Pvt. Ltd.  Field programmable logic device with efficient memory utilization 
US20040178818A1 (en)  20020610  20040916  Xilinx, Inc.  Programmable logic device having heterogeneous programmable logic blocks 
US20040193981A1 (en)  20030331  20040930  Iain Clark  Onchip scan clock generator for asic testing 
US6836839B2 (en)  20010322  20041228  Quicksilver Technology, Inc.  Adaptive integrated circuitry with heterogeneous and reconfigurable matrices of diverse and adaptive computational units having fixed, application specific computational elements 
EP1220108A3 (en)  20001026  20050112  Cypress Semiconductor Corporation  Programmable circuit 
US6874079B2 (en)  20010725  20050329  Quicksilver Technology  Adaptive computing engine with dataflow graph based sequencing in reconfigurable minimatrices of composite functional blocks 
US20050144215A1 (en)  20031229  20050630  Xilinx, Inc.  Applications of cascading DSP slices 
US20050166038A1 (en)  20020410  20050728  Albert Wang  Highperformance hybrid processor with configurable execution units 
US6924663B2 (en)  20011228  20050802  Fujitsu Limited  Programmable logic device with ferroelectric configuration memories 
US20050187999A1 (en)  20040220  20050825  Altera Corporation  Saturation and rounding in multiplyaccumulate blocks 
US6971083B1 (en)  20021113  20051129  Altera Corporation  Method for programming programmable logic device with blocks that perform multiplication and other arithmetic functions 
EP0992885B1 (en)  19981006  20051228  Texas Instruments France  Multiplier accumulator circuits 
US20070185952A1 (en)  20060209  20070809  Altera Corporation  Specialized processing block for programmable logic device 
US20070185951A1 (en)  20060209  20070809  Altera Corporation  Specialized processing block for programmable logic device 
US7912883B2 (en) *  20070802  20110322  Via Technologies, Inc.  Exponent processing systems and methods 
EP1031934B1 (en)  19990226  20111005  Texas Instruments Incorporated  Method and apparatus for dot product calculation 
Family Cites Families (12)
Publication number  Priority date  Publication date  Assignee  Title 

JPS61237133A (en)  19850415  19861022  Nec Corp  Arithmetic circuit 
JPH07135447A (en)  19931111  19950523  Sony Corp  Digital processing device 
US5553012A (en)  19950310  19960903  Motorola, Inc.  Exponentiation circuit utilizing shift means and method of using same 
US5721696A (en)  19950828  19980224  Motorola Inc.  Method and system for performing an FIR filtering operation 
US6247036B1 (en)  19960122  20010612  Infinite Technology Corp.  Processor with reconfigurable arithmetic data path 
US6624658B2 (en)  19990204  20030923  Advantage Logic, Inc.  Method and apparatus for universal program controlled bus architecture 
US6150837A (en)  19970228  20001121  Actel Corporation  Enhanced field programmable gate array 
DE69834942T2 (en)  19971217  20070606  Panasonic Europe Ltd., Uxbridge  Means for multiplying 
US7389487B1 (en)  19980428  20080617  Actel Corporation  Dedicated interface architecture for a hybrid integrated circuit 
US6150838A (en)  19990225  20001121  Xilinx, Inc.  FPGA configurable logic block with multipurpose logic/memory circuit 
WO2001013562A2 (en)  19990813  20010222  Comsat Corporation  A high speed burstmode digital demodulator architecture 
US7797363B2 (en)  20040407  20100914  Sandbridge Technologies, Inc.  Processor having parallel vector multiply and reduce operations with sequential semantics 

2008
 20080314 US US12/048,379 patent/US8244789B1/en active Active

2012
 20120710 US US13/545,405 patent/US8886695B1/en active Active
Patent Citations (246)
Publication number  Priority date  Publication date  Assignee  Title 

US3473160A (en)  19661010  19691014  Stanford Research Inst  Electronically controlled microelectronic cellular logic array 
US4215406A (en)  19720822  19800729  Westinghouse Electric Corp.  Digital computer monitored and/or operated system or process which is structured for operation with an improved automatic programming process and system 
US4215407A (en)  19720822  19800729  Westinghouse Electric Corp.  Combined file and directory system for a process control digital computer system 
US4179746A (en)  19760719  19791218  Texas Instruments Incorporated  Digital processor system with conditional carry and status function in arithmetic unit 
US4156927A (en)  19760811  19790529  Texas Instruments Incorporated  Digital processor system with direct access memory 
US4212076A (en)  19760924  19800708  Giddings & Lewis, Inc.  Digital computer structure providing arithmetic and boolean logic operations, the latter controlling the former 
US4484259A (en)  19800213  19841120  Intel Corporation  Fraction bus for use in a numeric data processor 
US4422155A (en)  19810401  19831220  American Microsystems, Inc.  Multiplier/adder circuit 
US4521907A (en)  19820525  19850604  American Microsystems, Incorporated  Multiplier/adder circuit 
US4597053A (en)  19830701  19860624  Codex Corporation  Twopass multiplier/accumulator circuit 
US4623961A (en)  19840307  19861118  Westinghouse Electric Corp.  Programmable controller having automatic contact line solving 
EP0158430B1 (en)  19840307  19910515  Westinghouse Electric Corporation  Programming controller having automatic contact line solving 
USRE34363E (en)  19840312  19930831  Xilinx, Inc.  Configurable electrical circuit having configurable logic elements and configurable interconnects 
US4727508A (en)  19841214  19880223  Motorola, Inc.  Circuit for adding and/or subtracting numbers in logarithmic representation 
US4682302A (en)  19841214  19870721  Motorola, Inc.  Logarithmic arithmetic logic unit 
US4718057A (en)  19850830  19880105  Advanced Micro Devices, Inc.  Streamlined digital signal processor 
US4791590A (en)  19851119  19881213  Cornell Research Foundation, Inc.  High performance signal processor 
US4823295A (en)  19861110  19890418  Harris Corp.  High speed signal processor 
US4799004A (en)  19870126  19890117  Kabushiki Kaisha Toshiba  Transfer circuit for operation test of LSI systems 
US4839847A (en)  19870414  19890613  Harris Corp.  Nclock, nbitserial multiplier 
US4982354A (en)  19870528  19910101  Mitsubishi Denki Kabushiki Kaisha  Digital finite impulse response filter and method 
US4994997A (en)  19870925  19910219  U.S. Philips Corporation  Pipelinetype serial multiplier circuit 
US4871930A (en)  19880505  19891003  Altera Corporation  Programmable logic device with array blocks connected via programmable interconnect 
US4967160A (en)  19880624  19901030  ThomsonCsf  Frequency multiplier with programmable order of multiplication 
US5452231A (en)  19881005  19950919  Quickturn Design Systems, Inc.  Hierarchically connected reconfigurable logic assembly 
US4912345A (en)  19881229  19900327  SgsThomson Microelectronics, Inc.  Programmable summing functions for programmable logic devices 
EP0380456B1 (en)  19890125  19960605  SGSTHOMSON MICROELECTRONICS S.r.l.  Field programmable logic and analogic integrated circuit 
US5550993A (en)  19890504  19960827  Texas Instruments Incorporated  Data processor with sets of two registers where both registers receive identical information and when context changes in one register the other register remains unchanged 
EP0411491B1 (en)  19890802  19990303  Cyrix Corporation  Method and apparatus for performing division using a rectangular aspect ratio multiplier 
US5128559A (en)  19890929  19920707  SgsThomson Microelectronics, Inc.  Logic block for programmable logic devices 
US5465226A (en)  19900320  19951107  Fujitsu Limited  High speed digital parallel multiplier 
US5523963A (en)  19900510  19960604  Xilinx, Inc.  Logic structure and circuit for fast carry 
US5267187A (en)  19900510  19931130  Xilinx Inc  Logic structure and circuit for fast carry 
EP0461798B1 (en)  19900614  19970813  Advanced Micro Devices, Inc.  Configurable interconnect structure 
US5768613A (en)  19900706  19980616  Advanced Micro Devices, Inc.  Computing apparatus configured for partitioned processing 
US5175702A (en)  19900718  19921229  International Business Machines Corporation  Digital signal processor architecture with plural multiply/accumulate devices 
EP0498066A2 (en)  19910208  19920812  Hitachi, Ltd.  Programmable logic controller 
US5122685A (en)  19910306  19920616  Quicklogic Corporation  Programmable application specific integrated circuit and logic cell therefor 
US5296759A (en)  19910829  19940322  National Semiconductor Corporation  Diagonal wiring between abutting logic cells in a configurable logic array 
US5371422A (en)  19910903  19941206  Altera Corporation  Programmable logic device having multiplexers and demultiplexers randomly connected to global conductors for interconnections between logic elements 
US5812479A (en)  19910903  19980922  Altera Corporation  Programmable logic array integrated circuits 
US5338983A (en)  19911028  19940816  Texas Instruments Incorporated  Application specific exclusive of based logic module architecture for FPGAs 
US5208491A (en)  19920107  19930504  Washington Research Foundation  Field programmable gate array 
US5465375A (en)  19920114  19951107  France Telecom  Multiprocessor system with cascaded modules combining processors through a programmable logic cell array 
EP0555092B1 (en)  19920207  19970514  Questech Limited  Improvements in and relating to digital filters 
US5636150A (en)  19920806  19970603  Sharp Kabushiki Kaisha  Data driven type digital filter unit and data driven type information processor including the same 
US5497498A (en)  19921105  19960305  Giga Operations Corporation  Video processing module using a second programmable logic device which reconfigures a first programmable logic device for data transformation 
US5357152A (en)  19921110  19941018  Infinite Technology Corporation  Logic system of logic networks with programmable selected functions and programmable operational controls 
EP0606653A1 (en)  19930104  19940720  Texas Instruments Incorporated  Field programmable distributed processing memory 
US5424589A (en)  19930212  19950613  The Board Of Trustees Of The Leland Stanford Junior University  Electrically programmable interchip interconnect architecture 
US5483178A (en)  19930329  19960109  Altera Corporation  Programmable logic device with logic block outputs coupled to adjacent logic block output multiplexers 
US5452375A (en)  19930524  19950919  Sagem S.A.  Digital image processing circuitry 
US5528550A (en)  19930528  19960618  Texas Instruments Incorporated  Apparatus, systems and methods for implementing memory embedded search arithmetic logic unit 
US5381357A (en)  19930528  19950110  Grumman Corporation  Complex adaptive fir filter 
US5500828A (en)  19930528  19960319  Texas Instruments Incorporated  Apparatus, system and methods for distributed signal processing 
US5537601A (en)  19930721  19960716  Hitachi, Ltd.  Programmable digital signal processor for performing a plurality of signal processings 
US5594912A (en)  19930809  19970114  Siemens Aktiengesellschaft  Digital signal processing device with optimized ALU circuit and logic block for controlling one of two registers based on the contents of the multiplication register 
US5457644A (en)  19930820  19951010  Actel Corporation  Field programmable digital signal processing array integrated circuit 
US5349250A (en)  19930902  19940920  Xilinx, Inc.  Logic structure and circuit for fast carry 
US5546018A (en)  19930902  19960813  Xilinx, Inc.  Fast carry structure with synchronous input 
US5740404A (en)  19930927  19980414  Hitachi America Limited  Digital signal processor with onchip select decoder and wait state generator 
US5404324A (en)  19931101  19950404  HewlettPackard Company  Methods and apparatus for performing division and square root computations in a computer 
GB2283602B (en)  19931104  19980304  Altera Corp  Implementation of redundancy on a programmable logic device 
US5640578A (en)  19931130  19970617  Texas Instruments Incorporated  Arithmetic logic unit having plural independent sections and register storing resultant indicator bit from every section 
US5590350A (en)  19931130  19961231  Texas Instruments Incorporated  Three input arithmetic logic unit with mask generator 
US5446651A (en)  19931130  19950829  Texas Instruments Incorporated  Split multiply operation 
US5961635A (en)  19931130  19991005  Texas Instruments Incorporated  Three input arithmetic logic unit with barrel rotator and mask generator 
US5596763A (en)  19931130  19970121  Texas Instruments Incorporated  Three input arithmetic logic unit forming mixed arithmetic and boolean combinations 
US6098163A (en)  19931130  20000801  Texas Instruments Incorporated  Three input arithmetic logic unit with shifter 
US5805913A (en)  19931130  19980908  Texas Instruments Incorporated  Arithmetic logic unit with conditional register source selection 
US5644522A (en)  19931130  19970701  Texas Instruments Incorporated  Method, apparatus and system for multiply rounding using redundant coded multiply result 
EP0657803B1 (en)  19931130  20020502  Texas Instruments Incorporated  Three input arithmetic logic unit 
EP0660227B1 (en)  19931130  20020502  Texas Instruments Incorporated  Three input arithmetic logic unit forming the sum of a first and a second boolean combination of the inputs 
US5995748A (en)  19931130  19991130  Texas Instruments Incorporated  Three input arithmetic logic unit with shifter and/or mask generator 
US5960193A (en)  19931130  19990928  Texas Instruments Incorporated  Apparatus and system for sum of plural absolute differences 
US5959871A (en)  19931223  19990928  Analogix/Portland State University  Programmable analog array circuit 
US5563526A (en)  19940103  19961008  Texas Instruments Incorporated  Programmable mixedmode integrated circuit architecture 
US5951673A (en)  19940125  19990914  Yamaha Corporation  Digital signal processing device capable of selectively imparting effects to input data 
GB2286737A (en)  19940217  19950823  Pilkington Germany No 2 Ltd  ASIC with multiple internal reconfiguration stores 
US5451948A (en)  19940228  19950919  Cubic Communications, Inc.  Apparatus and method for combining analog and digital automatic gain control in receivers with digital signal processing 
US6052755A (en)  19940328  20000418  Altera Corporation  Programming circuits and techniques for programmable logic 
US5563819A (en)  19940331  19961008  Cirrus Logic, Inc.  Fast high precision discretetime analog finite impulse response filter 
US5594366A (en)  19940504  19970114  Atmel Corporation  Programmable logic device with regional and universal signal routing 
US5655069A (en)  19940729  19970805  Fujitsu Limited  Apparatus having a plurality of programmable logic processing units for selfrepair 
US5794067A (en)  19941003  19980811  Ricoh Company, Ltd.  Digital signal processing device 
US5652903A (en)  19941101  19970729  Motorola, Inc.  DSP coprocessor for use on an integrated circuit that performs multiple communication tasks 
US5872380A (en)  19941102  19990216  Lsi Logic Corporation  Hexagonal sense cell architecture 
US5606266A (en)  19941104  19970225  Altera Corporation  Programmable logic array integrated circuits with enhanced output routing 
US5664192A (en)  19941214  19970902  Motorola, Inc.  Method and system for accumulating values in a computing device 
US5636368A (en)  19941223  19970603  Xilinx, Inc.  Method for programming complex PLD having more than one function block type 
US5963048A (en)  19941223  19991005  Xilinx, Inc.  Method for programming complex PLD having more than one function block type 
US5801546A (en)  19950104  19980901  Xilinx, Inc.  Interconnect architecture for field programmable gate array using variable length conductors 
US5633601A (en)  19950310  19970527  Texas Instruments Incorporated  Field programmable gate array logic module configurable as combinational or sequential circuits 
US5572148A (en)  19950322  19961105  Altera Corporation  Programmable logic array integrated circuit with generalpurpose memory configurable as a random access or FIFO memory 
US5570040A (en)  19950322  19961029  Altera Corporation  Programmable logic array integrated circuit incorporating a firstin firstout memory 
US5696708A (en)  19950330  19971209  Crystal Semiconductor  Digital filter with decimated frequency response 
US5689195A (en)  19950517  19971118  Altera Corporation  Programmable logic array integrated circuit devices 
US5790446A (en)  19950705  19980804  Sun Microsystems, Inc.  Floating point multiplier with reduced critical paths using delay matching techniques 
US5559450A (en)  19950727  19960924  Lucent Technologies Inc.  Field programmable gate array with multiport RAM 
US5570039A (en)  19950727  19961029  Lucent Technologies Inc.  Programmable function unit as parallel multiplier cell 
US5581501A (en)  19950817  19961203  Altera Corporation  Nonvolatile SRAM cells and cell arrays 
US5761483A (en)  19950818  19980602  Xilinx, Inc.  Optimizing and operating a time multiplexed programmable logic device 
US5646545A (en)  19950818  19970708  Xilinx, Inc.  Time multiplexed programmable logic device 
US5978260A (en)  19950818  19991102  Xilinx, Inc.  Method of time multiplexing a programmable logic device 
US5859878A (en)  19950831  19990112  Northrop Grumman Corporation  Common receive module for a programmable digital radio 
US6072994A (en)  19950831  20000606  Northrop Grumman Corporation  Digitally programmable multifunction radio system architecture 
US5729495A (en)  19950929  19980317  Altera Corporation  Dynamic nonvolatile memory cell 
US5648732A (en)  19951004  19970715  Xilinx, Inc.  Field programmable pipeline array 
US5744991A (en)  19951016  19980428  Altera Corporation  System for distributing clocks using a delay lock loop in a programmable logic circuit 
US5617058A (en)  19951113  19970401  Apogee Technology, Inc.  Digital signal processing for linearization of small input signals to a tristate power switch 
EP0868659B1 (en)  19951218  20020807  Abb Ab  Torque transducer 
US5894228A (en)  19960110  19990413  Altera Corporation  Tristate structures for programmable logic devices 
US5898602A (en)  19960125  19990427  Xilinx, Inc.  Carry chain circuit with flexible carry function for implementing arithmetic and logical functions 
US5754459A (en)  19960208  19980519  Xilinx, Inc.  Multiplier circuit design for a programmable logic device 
US5744980A (en)  19960216  19980428  Actel Corporation  Flexible, highperformance static RAM architecture for fieldprogrammable gate arrays 
US5764555A (en)  19960313  19980609  International Business Machines Corporation  Method and system of rounding for division or square root: eliminating remainder calculation 
US6005806A (en)  19960314  19991221  Altera Corporation  Nonvolatile configuration cells and cell arrays 
US5777912A (en)  19960328  19980707  Crystal Semiconductor Corporation  Linear phase finite impulse response filter with preaddition 
US5869979A (en)  19960405  19990209  Altera Corporation  Technique for preconditioning I/Os during reconfiguration 
US5986465A (en)  19960409  19991116  Altera Corporation  Programmable logic integrated circuit architecture incorporating a global shareable expander 
US5949710A (en)  19960410  19990907  Altera Corporation  Programmable interconnect junction 
US5784636A (en)  19960528  19980721  National Semiconductor Corporation  Reconfigurable computer architecture for use in signal processing applications 
US5956265A (en)  19960607  19990921  Lewis; James M.  Boolean digital multiplier 
US6130554A (en)  19960621  20001010  Quicklogic Corporation  Programmable integrated circuit having a test circuit for testing the integrity of routing resource structures 
US5880981A (en)  19960812  19990309  Hitachi America, Ltd.  Method and apparatus for reducing the power consumption in a programmable digital signal processor 
US6031763A (en)  19960816  20000229  Altera Corporation  Evaluation of memory cell characteristics 
US5838165A (en)  19960821  19981117  Chatter; Mukesh  High performance self modifying onthefly alterable logic FPGA, architecture and method 
EP0927393B1 (en)  19960923  20011017  ARM Limited  Digital signal processing integrated circuit architecture 
US5805477A (en)  19960926  19980908  HewlettPackard Company  Arithmetic cell for field programmable devices 
US5825202A (en)  19960926  19981020  Xilinx, Inc.  Integrated circuit with field programmable and application specific logic areas 
GB2318198B (en)  19961010  20001025  Altera Corp  Architectures for programmable logic devices 
US5942914A (en)  19961025  19990824  Altera Corporation  PLD with split multiplexed inputs from global conductors 
US5892962A (en)  19961112  19990406  Lucent Technologies Inc.  FPGAbased processor 
US5812562A (en)  19961115  19980922  Samsung Electronics Company, Ltd.  Low cost emulation scheme implemented via clock control using JTAG controller in a scan environment 
US6009451A (en)  19961122  19991228  Lucent Technologies Inc.  Method for generating barrel shifter result flags directly from input data 
US5841684A (en)  19970124  19981124  Vlsi Technology, Inc.  Method and apparatus for computer implemented constant multiplication with multipliers having repeated patterns including shifting of replicas and patterns having at least two digit positions with nonzero values 
US5815422A (en)  19970124  19980929  Vlsi Technology, Inc.  Computerimplemented multiplication with shifting of patternproduct partials 
US5821776A (en)  19970131  19981013  Actel Corporation  Field programmable gate array with mask programmed analog function circuits 
US5982195A (en)  19970220  19991109  Altera Corporation  Programmable logic device architectures 
US5999015A (en)  19970220  19991207  Altera Corporation  Logic region resources for programmable logic devices 
US5931898A (en)  19970225  19990803  Lucent Technologies Inc  Finite impulse response filter 
US6064614A (en)  19970225  20000516  Lucent Technologies  Finite impulse response filter 
US5963050A (en)  19970226  19991005  Xilinx, Inc.  Configurable logic element with fast feedback paths 
US5874834A (en)  19970304  19990223  Xilinx, Inc.  Field programmable gate array with distributed gatearray functionality 
US6728901B1 (en)  19970310  20040427  Janusz Rajski  Arithmetic builtin selftest of multiple scanbased integrated circuits 
US5991898A (en)  19970310  19991123  Mentor Graphics Corporation  Arithmetic builtin self test of multiple scanbased integrated circuits 
US5991788A (en)  19970314  19991123  Xilinx, Inc.  Method for configuring an FPGA for large FFTs and other vector rotation computations 
US6041340A (en)  19970314  20000321  Xilinx, Inc.  Method for configuring an FPGA for large FFTs and other vector rotation computations 
US5847579A (en)  19970320  19981208  Xilinx, Inc.  Programmable logic array with improved interconnect structure 
US6020759A (en)  19970321  20000201  Altera Corporation  Programmable logic array device with random access memory configurable as product terms 
US5878250A (en)  19970407  19990302  Altera Corporation  Circuitry for emulating asynchronous register loading functions 
US6107820A (en)  19970523  20000822  Altera Corporation  Redundancy circuitry for programmable logic devices with interleaved input circuits 
US6006321A (en)  19970613  19991221  Malleable Technologies, Inc.  Programmable logic datapath that may be used in a field programmable device 
US6351142B1 (en)  19970613  20020226  PmcSierra, Inc.  Programmable logic datapath that may be used in a field programmable device 
US6531888B2 (en)  19970613  20030311  PmcSierra, Inc.  Programmable logic datapath that may be used in a field programmable device 
US5970254A (en)  19970627  19991019  Cooke; Laurence H.  Integrated processor and programmable data path chip for reconfigurable computing 
US6085317A (en)  19970815  20000704  Altera Corporation  Reconfigurable computer architecture using programmable logic devices 
EP0909028B1 (en)  19970916  20030702  Tektronix, Inc.  Fir filter for programmable decimation 
US6286024B1 (en)  19970918  20010904  Kabushiki Kaisha Toshiba  Highefficiency multiplier and multiplying method 
US5944774A (en)  19970926  19990831  Ericsson Inc.  Methods apparatus and computer program products for accumulating logarithmic values 
US6021423A (en)  19970926  20000201  Xilinx, Inc.  Method for parallelefficient configuring an FPGA for large FFTS and other vector rotation computations 
EP0905906A2 (en)  19970926  19990331  Lucent Technologies Inc.  Hybrid programmable gate arrays 
US6069487A (en)  19971014  20000530  Altera Corporation  Programmable logic device circuitry for improving multiplier speed and/or efficiency 
US6052327A (en)  19971014  20000418  Altera Corporation  Dualport programmable logic device variable depth and width memory array 
US6107824A (en)  19971016  20000822  Altera Corporation  Circuitry and methods for internal interconnection of programmable logic devices 
US6157210A (en)  19971016  20001205  Altera Corporation  Programmable logic device with circuitry for observing programmable logic circuit signals and for preloading programmable logic circuits 
US6029187A (en)  19971028  20000222  Atmel Corporation  Fast regular multiplier architecture 
US6091765A (en)  19971103  20000718  Harris Corporation  Reconfigurable radio system architecture 
US6065131A (en)  19971126  20000516  International Business Machines Corporation  Multispeed DSP kernel and clock mechanism 
US6075381A (en)  19980121  20000613  Micron Electronics, Inc.  Programmable logic block in an integrated circuit 
US6279021B1 (en)  19980130  20010821  Sanyo Electric Co. Ltd.  Digital filters 
US6094726A (en)  19980205  20000725  George S. Sheng  Digital signal processor using a reconfigurable array of macrocells 
US6175849B1 (en)  19980210  20010116  Lucent Technologies, Inc.  System for digital filtering in a fixed number of clock cycles 
US6097988A (en)  19980210  20000801  Advanced Micro Devices, Inc.  Logic system and method employing multiple configurable logic blocks and capable of implementing a state machine using a minimum amount of configurable logic 
US6167415A (en)  19980210  20001226  Lucent Technologies, Inc.  Recursive digital filter with reset 
US6367003B1 (en)  19980304  20020402  Micron Technology, Inc.  Digital signal processor having enhanced utilization of multiply accumulate (MAC) stage and method 
US6154049A (en)  19980327  20001128  Xilinx, Inc.  Multiplier fabric for use in field programmable gate arrays 
US5968196A (en)  19980421  19991019  Atmel Corporation  Configuration control in a programmable logic device using nonvolatile elements 
US6242947B1 (en)  19980424  20010605  Xilinx, Inc.  PLD having a window pane architecture with segmented interconnect wiring between logic block arrays 
US6084429A (en)  19980424  20000704  Xilinx, Inc.  PLD having a window pane architecture with segmented and staggered interconnect wiring between logic block arrays 
US6226735B1 (en)  19980508  20010501  Broadcom  Method and apparatus for configuring arbitrary sized data paths comprising multiple context processing elements 
US20010029515A1 (en)  19980508  20011011  Mirsky Ethan A.  Method and apparatus for configuring arbitrary sized data paths comprising multiple context processing elements 
US6591357B2 (en)  19980508  20030708  Broadcom Corporation  Method and apparatus for configuring arbitrary sized data paths comprising multiple context processing elements 
US6140839A (en)  19980513  20001031  Kaviani; Alireza S.  Computational field programmable architecture 
US5999990A (en)  19980518  19991207  Motorola, Inc.  Communicator having reconfigurable resources 
US6066960A (en)  19980521  20000523  Altera Corporation  Programmable logic device having combinational logic at inputs to logic elements within logic array blocks 
US6314442B1 (en)  19980619  20011106  Mitsubishi Denki Kabushiki Kaisha  Floatingpoint arithmetic unit which specifies a least significant bit to be incremented 
US6314551B1 (en)  19980622  20011106  Morgan Stanley & Co. Incorporated  System processing unit extended with programmable logic for plurality of functions 
US6467017B1 (en)  19980623  20021015  Altera Corporation  Programmable logic device having embedded dualport random access memory configurable as singleport memory 
US6163788A (en)  19980625  20001219  Industrial Technology Research Institute  Programmable finite impulse response processor with scalable dynamic data range 
US6073154A (en)  19980626  20000606  Xilinx, Inc.  Computing multidimensional DFTs in FPGA 
US6321246B1 (en)  19980916  20011120  Cirrus Logic, Inc.  Linear phase FIR sinc filter with multiplexing 
EP0992885B1 (en)  19981006  20051228  Texas Instruments France  Multiplier accumulator circuits 
US6571268B1 (en)  19981006  20030527  Texas Instruments Incorporated  Multiplier accumulator circuits 
US6453382B1 (en)  19981105  20020917  Altera Corporation  Content addressable memory encoded outputs 
US6091261A (en)  19981112  20000718  Sun Microsystems, Inc.  Apparatus and method for programmable delays using a boundaryscan chain 
US6215326B1 (en)  19981118  20010410  Altera Corporation  Programmable logic device architecture with superregions having logic regions and a memory region 
US6591283B1 (en)  19981224  20030708  Stmicroelectronics N.V.  Efficient interpolator for high speed timing recovery 
US6243729B1 (en)  19981231  20010605  Texas Instruments Incorporated  Digital finiteimpulseresponse (FIR) filter with a modified architecture based on high order RadixN numbering 
US6366944B1 (en)  19990115  20020402  Razak Hossain  Method and apparatus for performing signed/unsigned multiplication 
US6107821A (en)  19990208  20000822  Xilinx, Inc.  Onchip logic analysis and method for using the same 
EP1031934B1 (en)  19990226  20111005  Texas Instruments Incorporated  Method and apparatus for dot product calculation 
US6407576B1 (en)  19990304  20020618  Altera Corporation  Interconnection and input/output resources for programmable logic integrated circuit devices 
US6323680B1 (en)  19990304  20011127  Altera Corporation  Programmable logic device configured to accommodate multiplication 
US6359468B1 (en)  19990304  20020319  Altera Corporation  Programmable logic device with carry lookahead 
US6480980B2 (en)  19990310  20021112  Nec Electronics, Inc.  Combinational test pattern generation method and apparatus 
US6557092B1 (en)  19990329  20030429  Greg S. Callen  Programmable ALU 
US6904471B2 (en)  19990330  20050607  Siemens Energy & Automation, Inc.  Programmable logic controller customized function call method, system and apparatus 
US6745254B2 (en)  19990330  20040601  Siemens Energy & Automation, Inc.  Programmable logic controller method, system and apparatus 
EP1058185A1 (en)  19990531  20001206  Motorola, Inc.  A multiply and accumulate apparatus and a method thereof 
US6246258B1 (en)  19990621  20010612  Xilinx, Inc.  Realizing analogtodigital converter on a digital programmable integrated circuit 
US6438570B1 (en)  19990721  20020820  Xilinx, Inc.  FPGA implemented bitserial multiplier and infinite impulse response 
US6542000B1 (en)  19990730  20030401  Iowa State University Research Foundation, Inc.  Nonvolatile programmable logic devices 
US6600788B1 (en)  19990910  20030729  Xilinx, Inc.  Narrowband filter including sigmadelta modulator implemented in a programmable logic device 
US6725441B1 (en)  20000322  20040420  Xilinx, Inc.  Method and apparatus for defining and modifying connections between logic cores implemented on programmable logic devices 
US6574762B1 (en)  20000331  20030603  Lsi Logic Corporation  Use of a scan chain for configuration of BIST unit operation 
US6362650B1 (en)  20000518  20020326  Xilinx, Inc.  Method and apparatus for incorporating a multiplier into an FPGA 
US6573749B2 (en)  20000518  20030603  Xilinx, Inc.  Method and apparatus for incorporating a multiplier into an FPGA 
US6407694B1 (en)  20000614  20020618  Raytheon Company  General purpose filter 
US6744278B1 (en)  20000902  20040601  Actel Corporation  Tileable fieldprogrammable gate array architecture 
US6731133B1 (en)  20000902  20040504  Actel Corporation  Routing structures for a tileable fieldprogrammable gate array architecture 
US6538470B1 (en)  20000918  20030325  Altera Corporation  Devices and methods with programmable logic and digital signal processing regions 
US6628140B2 (en)  20000918  20030930  Altera Corporation  Programmable logic devices with functionspecific blocks 
US20020089348A1 (en)  20001002  20020711  Martin Langhammer  Programmable logic integrated circuit devices including dedicated processor components 
EP1220108A3 (en)  20001026  20050112  Cypress Semiconductor Corporation  Programmable circuit 
US6483343B1 (en)  20001229  20021119  Quicklogic Corporation  Configurable computational unit embedded in a programmable device 
US6836839B2 (en)  20010322  20041228  Quicksilver Technology, Inc.  Adaptive integrated circuitry with heterogeneous and reconfigurable matrices of diverse and adaptive computational units having fixed, application specific computational elements 
US20030088757A1 (en)  20010502  20030508  Joshua Lindner  Efficient high performance data operation element for use in a reconfigurable logic environment 
US6788104B2 (en)  20010629  20040907  Stmicroelectronics Pvt. Ltd.  Field programmable logic device with efficient memory utilization 
US6874079B2 (en)  20010725  20050329  Quicksilver Technology  Adaptive computing engine with dataflow graph based sequencing in reconfigurable minimatrices of composite functional blocks 
US6556044B2 (en)  20010918  20030429  Altera Corporation  Programmable logic device including multipliers and configurations thereof to reduce resource utilization 
US6924663B2 (en)  20011228  20050802  Fujitsu Limited  Programmable logic device with ferroelectric configuration memories 
US6700581B2 (en)  20020301  20040302  3D Labs Inc., Ltd.  Incircuit test using scan chains 
US20050166038A1 (en)  20020410  20050728  Albert Wang  Highperformance hybrid processor with configurable execution units 
US6781408B1 (en)  20020424  20040824  Altera Corporation  Programmable logic device with routing channels 
US20040178818A1 (en)  20020610  20040916  Xilinx, Inc.  Programmable logic device having heterogeneous programmable logic blocks 
US20040064770A1 (en)  20020930  20040401  Xin Weizhuang (Wayne)  Programmable state machine of an integrated circuit 
US20040083412A1 (en)  20021025  20040429  International Business Machines Corporation  Testing logic and embedded memory in parallel 
US6971083B1 (en)  20021113  20051129  Altera Corporation  Method for programming programmable logic device with blocks that perform multiplication and other arithmetic functions 
US6774669B1 (en)  20021230  20040810  Actel Corporation  Field programmable gate array freeway architecture 
US20040193981A1 (en)  20030331  20040930  Iain Clark  Onchip scan clock generator for asic testing 
US20050144215A1 (en)  20031229  20050630  Xilinx, Inc.  Applications of cascading DSP slices 
US20050187999A1 (en)  20040220  20050825  Altera Corporation  Saturation and rounding in multiplyaccumulate blocks 
US20070185952A1 (en)  20060209  20070809  Altera Corporation  Specialized processing block for programmable logic device 
US20070185951A1 (en)  20060209  20070809  Altera Corporation  Specialized processing block for programmable logic device 
US7912883B2 (en) *  20070802  20110322  Via Technologies, Inc.  Exponent processing systems and methods 
NonPatent Citations (64)
Title 

"Implementing Logic with the Embedded Array in FLEX 10K Devices", Altera, May 2001, ver 2.1. 
"Implementing Multipliers in FLEX 10K EABs", Altera, Mar. 1996. 
"QuickDSP(TM) Family Data Sheet", Quicklogic, Aug. 7, 2001, revision B. 
"QuickDSP™ Family Data Sheet", Quicklogic, Aug. 7, 2001, revision B. 
"The QuickDSP Design Guide", Quicklogic, Aug. 2001, revision B. 
"VirtexII 1.5V FieldProgrammable Gate Arrays", Xilinx, Apr. 2, 2001, module 1 of 4. 
"VirtexII 1.5V FieldProgrammable Gate Arrays", Xilinx, Apr. 2, 2001, module 2 of 4. 
"VirtexII 1.5V FieldProgrammable Gate Arrays", Xilinx, Jan. 25, 2001, module 2 of 4. 
"Xilinx Announces DSP Algorithms, Tools and Features for VirtexII Architecture", Xilinx, Nov. 21, 2000. 
"Xilinx Unveils New FPGA Architecture to Enable HighPerformance, 10 Million System Gate Designs", Xilinx, Jun. 22, 2000. 
Amos, D., "PLD architectures match DSP algorithms," Electronic Product Design, vol. 17, No. 7, Jul. 1996, pp. 30, 32. 
Analog Devices, Inc., The Applications Engineering Staff of Analog Devices, DSP Division, Digital Signal Processing Applications Using the ADSP2100 Family (edited by Amy Mar), 1990, pp. 141192. 
Andrejas, J., et al., "Reusable DSP functions in FPGAs," FieldProgrammable Logic and Applications. Roadmap to Reconfigurable Computing. 10th International Conference, FPL 2000. Proceedings (Lecture Notes in Computer Science vol. 1896), Aug. 2730, 2000, pp. 456461. 
Aoki, T., "Signedweight arithmetic and its application to a fieldprogrammable digital filter architecture," IEICE Transactions on Electronics , 1999 , vol. E82C, No. 9, Sep. 1999, pp. 16871698. 
Ashour, M.A., et al., "An FPGA implementation guide for some different types of serialparallel multiplierstructures," Microelectronics Journal, vol. 31, No. 3, 2000, pp 161168. 
Berg. B.L., et al.,"Designing Power and Areas Efficient Multistage FIR Decimators with Economical Low Order Filters," ChipCenter Technical Note, Dec. 2001. 
Bursky, D., "Programmable Logic Challenges Traditional ASIC SoC Designs", Electronic Design, Apr. 15, 2002. 
Chhabra A. et al., Texas Instruments Inc., "A Block Floating Point Implementation on the TMS320C54x DSP", Application Report SPRA610, Dec. 1999, pp. 110. 
Colet, p., "When DSPs and FPGAs meet: Optimizing image processing architectures," Advanced Imaging, vol. 12, No. 9, Sep. 1997, pp. 14, 16, 18. 
Crookes, D., et al., "Design and implementation of a high level programming environment for FPGAbased processing," IEE ProceedingsVision, Image and Signal Processing, vol. 147, No. 4, Aug. 2000, pp. 377384. 
Crookes, D., et al., "Design and implementation of a high level programming environment for FPGAbased processing," IEE Proceedings—Vision, Image and Signal Processing, vol. 147, No. 4, Aug. 2000, pp. 377384. 
Debowski, L., et al., "A new flexible architecture of digital control systems based on DSP and complex CDLP technology for power conversion applications," PCIM 2000: Europe Official Proceedings of the ThirtySeventh International Intelligent Motion Conference, Jun. 68, 2000, pp. 281286. 
Dick C., et al., "Configurable logic for digital communications: some signal processing perspectives," IEEE Communications Magazine, vol. 37, No. 8, Aug. 1999, pp. 107111. 
Do, T.T., et al., "A flexible implementation of highperformance FIR filters on Xilinx FGPAs," FieldProgrammable Logic and Applications: From FPGAs to Computing Paradigm, 8th International Workshop, FPL'98, Proceedings, Hartenstein, R.W., et al., eds., Aug. 31Sep. 3, 1998, pp. 441445. 
Faura et al., "A Novel Mixed Signal Programmable Device With OnChip Microprocessor," Custom Integrated Circuits Conference, 1997, Proceedings of the IEEE 1997 Santa Clara, CA, USA, May 5, 1997, pp. 103106. 
Gaffar, A.A., et al., "FloatingPoint Bitwidth Analysis via Automatic Differentiation," IEEE Conference on Field Programmable Technology, Hong Kong, Dec. 2002. 
Guccione, S.A., "RunTime Reconfiguration at Xilinx," Parallel and distributed processing: 15 IPDPS 2000 workshops,Rolim. J., ed., May 15, 2000, p. 873. 
Hauck, S., "The Future of Reconfigurable Systems," Keynote Address, 5th Canadian Conference on Field Programmable Devices, Jun. 1998, http://www.ee.washington.edu/people/faculty/hauck/publications/ReconfigFuture.PDF. 
Heysters, P.M., et al., "Mapping of DSP algorithms on field programmable function arrays," FieldProgrammable Logic and Applications, Roadmap to Reconfigurable Computing. 10th International Conference, FPL 2000, Proceedings (Lecture Notes in Computer Science vol. 1896), Aug. 2730, 2000, pp. 400411. 
Huang, J., et al., "Simulated Performance of 1000BASET Receiver with Different Analog Front End Designs," Proceedings of the 35th Asilomar Conference on Signals, Systems, and Computers, Nov. 47, 2001. 
Jinghua Li, "Design a pocket multibit multiplier in FPGA," 1996 2nd International Conference on ASIC Proceedings (IEEE Cat No. 96TH8140), Oct. 2124, 1996, pp. 275279. 
Jones, G., "Fieldprogrammable digital signal conditioning," Electronic Product Design, vol. 21, No. 6, Jun. 2000, pp. C36C38. 
Kiefer, R., et al., "Performance comparison of software/FPGA hardware partitions for a DSP applications," 14th Australian microelectronics Conference, Microelectronics: Technology Today for the Future, MICRO '97 Proceedings, Sep. 28Oct. 1, 1997, pp. 8893. 
Kramberger, I., "DSP acceleration using a reconfigurable FPGA," ISIE '99, Proceedings of the IEEE International Symposium on Industrial Electronics (Cat No. 99TH8465), vol. 3 , Jul. 1216, 1999, pp. 15221525. 
Langhammer, M., "How to implement DSP in programmable logic," Elettronica Oggi, No. 266, Dec. 1998, pp. 113115. 
Langhammer, M., "Implementing a DSP in Programmable Logic," Online EE Times, May 1998, http://www.eetimes.com/editorial/1998/coverstory9805.html. 
Lattice Semiconductor Corp, ORCA ® FPGA Express (TM)Interface Manual: ispLEVER® Version 3.0, 2002. 
Lattice Semiconductor Corp, ORCA ® FPGA Express ™Interface Manual: ispLEVER® Version 3.0, 2002. 
Lazaravich, B.V., "Function block oriented field programmable logic arrays," Motorola, Inc. Technical Developments, vol. 18, Mar. 1993, pp. 1011. 
Lucent Technologies, Microelectronics Group, "Implementing and Optimizing Multipliers in ORCA(TM) FPGAs,", Application Note.AP97008FGPA, Feb. 1997. 
Lucent Technologies, Microelectronics Group, "Implementing and Optimizing Multipliers in ORCA™ FPGAs,", Application Note.AP97008FGPA, Feb. 1997. 
Lund, D., et al., "A new development system for reconfigurable digital signal processing," First International Conference on 3G Mobile Communication Technologies (Conf. Publ. No. 471), Mar. 2729, 2000, pp. 306310. 
Miller, N.L., et al., "Reconfigurable integrated circuit for high performance computer arithmetic," Proceedings of the 1998 IEE Colloquium on Evolvable Hardware Systems (Digest), No. 233. 1998, pp. 2/12/4. 
Mintzer, L., "Xilinx FPGA as an FFT processor," Electronic Engineering, vol. 69, No. 845, May 1997, pp. 81, 82, 84. 
Nozal, L., et al., "A new vision system: programmble logic devices and digital signal processor architecture (PLD+DSP)," Proceedings IECON '91, 1991 International Conference on Industrial Electronics, Control and Instrumentation (Cat. No. 91CH29769), vol. 3, Oct. 28Nov. 1, 1991, pp. 20142018. 
Papenfuss, J.R, et al., "Implementation of a realtime, frequency selective, RF channel simulator using a hybrid DSPFPGA architecture," RAWCON 2000: 2000 IEEE Radio and Wireless Conference (Cat. No. 00EX404), Sep. 1013, 2000, pp. 135138. 
Parhami, B., "Configurable arithmetic arrays with datadriven control," 34th Asilomar Conference on Signals, Systems and Computers, vol. 1, 2000. pp. 8993. 
Rangasayee, K., "Complex PLDs let you produce efficient anthmetic designs," EDN (European Edition), vol. 41, No. 13, Jun. 20, 1996, pp. 109, 110, 112, 114, 116. 
Rosado, A., et al., "A highspeed multiplier coprocessor unit based on FPGA," Journal of Electronical Engineering, vol. 48, No. 1112, 1997, pp. 298302. 
SantillanQ., G.F., et al., "Realtime integer convolution implemented using systolic arrays and a digitserial architecture in complex programmable logic devices," Proceedings of the Third International Workshop on Design of MixedMode Integrated Circuits and Applications (Cat. No. 99EX303), Jul. 2628, 1999, pp. 147150. 
Texas Instruments Inc., "TMS320C54x DSP Reference Set, vol. 1: CPU and Peripherals", Literature No. SPRU131F, Apr. 1999, pp. 21 through 216 and 41 through 429. 
Tisserand, A., et al., "An online arithmetic based FPGA for low power custom computing," Field Programmable Logic and Applications, 9th International Workshop, FPL '99, Proceedings (Lecture Notes in Computer Science vol. 1673), Lysaght, P., et al., eds., Aug. 30Sep. 1, 1999, pp. 264273. 
Tralka, C., "Symbiosis of DSP and PLD," Elektronik, vol. 49, No. 14 , Jul. 11, 2000, pp. 8496. 
Valls, J., et al., "A Study About FPGABased Digital Filters," Signal Processing Systems, 1998, SIPS 98, 1998 IEEE Workshop, Oct. 10, 1998, pp. 192201. 
Walters, A.L., "A Scalable FIR Filter Implementation Using 32bit FloatingPoint Complex Arithmetic on ,a FPGA Based Custom Computing Platform," Allison L. Walters, Thesis Submitted to the Faculty of Virginia Polytechnic Institute and State University, Jan. 30, 1998. 
Weisstein, E.W., "Karatsuba Multiplication," MathWorldA Wolfram Web Resource (Dec. 9, 2007), accessed Dec. 11, 2007 at http://mathworld.wolfram.com/KaratsubaMultiplication.html. 
Weisstein, E.W., "Karatsuba Multiplication," MathWorld—A Wolfram Web Resource (Dec. 9, 2007), accessed Dec. 11, 2007 at http://mathworld.wolfram.com/KaratsubaMultiplication.html. 
Wenzel, L., "Field programmable gate arrays (FPGAs) to replace digital signal processor integrated circuits," Elektronik , vol. 49, No. 5, Mar. 7, 2000, pp. 7886. 
Xilinx Inc., "Using Embedded Multipliers", VirtexII Platform FPGA Handbook, UG002 (v1.3), Dec. 3, 2001, pp. 251257. 
Xilinx Inc., "VirtexII 1.5V FieldProgrammable Gate Arrays", Advance Product Specification, DS0312 (v1.9), Nov. 29, 2001, module 2 of 4, pp. 139. 
Xilinx, Inc., "A 1D Systolic FIR," copyright 19942002, downloaded from http://www.iro.umontreal.ca/~aboulham/F6221/Xilinx%20A%201D%20systolic%20FIR.htm. 
Xilinx, Inc., "A 1D Systolic FIR," copyright 19942002, downloaded from http://www.iro.umontreal.ca/˜aboulham/F6221/Xilinx%20A%201D%20systolic%20FIR.htm. 
Xilinx, Inc., "The Future of FPGA's," White Paper. available Nov. 14, 2005 for downloaded from http://www.xilinx.com/prsrls,5yrwhite.htm. 
Xilinx, Inc., "The Future of FPGA's," White Paper. available Nov. 14, 2005 for downloaded from http://www.xilinx.com/prs—rls,5yrwhite.htm. 
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